Najaf or al-Najf al-Ashraf (Arabic: النَّجَف الاَشرَف) (Dignified Najaf) is a Shiite pilgrimage city in Iraq, where the Holy Shrine of Imam 'Ali (a) is located. The city was residential before the emergence of Islam, but after the construction of Imam 'Ali's mausoleum and shrine in 2nd century, it turned into a thriving city to which many Shi'as immigrated. Some kings, including 'Adud al-Dawla al-Daylami, Shah Isma'il, and Shah Tahmasp, as well as certain Qajar kings, contributed to the construction of Najaf.

The Islamic Seminary of Najaf is one of the oldest Islamic seminaries. According to historical accounts, it was founded by al-Shaykh al-Tusi in the 5th century. Many scholars and jurisprudents studied in the Seminary of Najaf, including Al-Shaykh Murtada al-Ansari, Muhammad Kazim Akhund Khurasani, Sayyid Muhammad Kazim Tabataba'i Yazdi, Sayyid Muhsin Hakim, Al-Sayyid Abu l-Qasim al-Khoei, and Sayyid 'Ali Sistani.

The Mosque of al-Shaykh al-Ansari, the Hannana Mosque, and Masjid al-Khadra' are well-known mosques in Najaf. There are many libraries and publication institutes in Najaf, including Haydariyya Library and Print House, Bahr al-'Ulum Library, and Murtadawiyya Print House.

According to 2017 statistics, the population of the city of Najaf amounts to around 800,000, almost all of whom are Muslims and Shi'as.